Question

我有以下课程：import { Component, OnInit } from '@angular/core'; import { ProjectService } from '../services/project.service'; import { Router, ActivatedRoute } from '@angular/router'; import { Location } from '@angular/common'; import { DomSanitizer } from '@angular/platform-browser'; import { environment } from '../../../../environments/environment'; @Component({ selector: 'app-project-details', templateUrl: './project-details.component.html', styleUrls: ['./project-details.component.css'] }) export class ProjectDetailsComponent implements OnInit { project: any; apiUrl: string; project_id: string; constructor( private router: Router, private activatedRoute: ActivatedRoute, private projectService: ProjectService, private _location: Location, private sanitization: DomSanitizer ) { this.apiUrl = environment.apiUrl; this.activatedRoute.params .subscribe(params => { console.log(params.project_id) this.project_id = params.project_id; this.getProjectByID(params.project_id); }) } ngOnInit() { } getProjectByID(project_id: string) { this.projectService.getProjectById(project_id).subscribe((data: any) => { data.project.projectImages.map(image => { image.path = this.sanitization.bypassSecurityTrustUrl(`${this.apiUrl}/${image.path}`); return image; }); this.project = data.project; }, err => { console.log(err); }); } Item是父类，Swords和food继承了Item类。我想为这些类中的每一个提供一堆不同的功能和描述。我完全了解事物的功能方面，但是我在努力寻找如何用子类覆盖默认描述的方法。

我目前在SQLAlchemy中使用单表继承。

Answer 1

信贷请Mike Bayer帮助我弄清楚如何改写__init__()以适合我的需要。如果有人能找到更优雅的解决方案，我将很乐意接受该答案。

class User(Base):
    __tablename__ = 'users'

    id = Column(Integer, primary_key=True)
    name = Column(String, default="User")
    fullname = Column(String)
    email = Column(String)
    type = Column(String)

    __mapper_args__ = {
        'polymorphic_on': type,
        'polymorphic_identity': 'user'
    }

    def __init__(self, **kwargs):
        super().__init__(**kwargs)

    def __repr__(self):
        return f"<User(id={self.id}, name='{self.name}', fullname='{self.fullname}', email='{self.email}')>"

    def is_admin(self):
        print(f"I, {self.name}, am NOT an admin")


class Admin(User):
    def __init__(self, **kwargs):
        kwargs.setdefault("name", "Admin")
        super().__init__(**kwargs)

    __mapper_args__ = {
        'polymorphic_identity': 'admin'
    }

如何在SQL Alchemy中访问/覆盖父级属性的默认值？

1 个答案: